| abstract |
The invention relates to preservative systems which are particularly suitable in cosmetic and dermatological preparations. The preservative system which comprises a cationic surfactant, derived from the condensation of fatty acids and esterified dibasic amino acids, having the formula (I) where: X − is Br − , Cl − , or HSO 4 R 1 : is a straight alkyl chain from an acid or saturated fatty hydroxy acid from 8 to 14 atoms of carbon bonded to the α-amino acid group through amidic bond. R 2 : is a straight or branched alkyl chain from 1 to 18 carbon atoms or aromatic. R 3 : is: (II) where n can be from 0 to 4, is combined with at least one other ionic or non-ionic preservative agent, whereby the combination displays a synergetic activity. A preservative system, wherein the cationic surfactant preservative derived from the condensation of fatty acids and esterified dibasic amino acid is LAE is particularly preferred. The other ionic or non ionic preservative agent is preferably at least one component selected from the group consisting of 2-bromo-2-nitro-1,3-propanediol (bronopol), parbens, imidazolidinyl urea, phenoxyethanol, DMDM hydantoin, 2-methyl-5-chloro-3,4-isothiazolinone/2-methyl-3,4-isothiazolinone and quaternium-15. |